/*
 * Copyright ©2021 su binglun(9085309@qq.com). All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *---------------------------------------------------------------------
 *-                                                                   -
 *-           Website : http://phoenix.sunny360.cn/                   -
 *-                                                                   -
 *---------------------------------------------------------------------
 */
package cn.sunny360.core.common;

import io.vertx.core.Promise;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.http.ServerWebSocket;
import io.vertx.core.impl.logging.Logger;
import io.vertx.core.impl.logging.LoggerFactory;

import java.util.ArrayList;
import java.util.List;

/**
 * WebSocket消息拦截器执行链
 * @author sublun
 */
public class MessageInterceptorChain {

    private static Logger logger = LoggerFactory.getLogger(MessageInterceptorChain.class);

    private List<MessageInterceptor> interceptors;

    MessageInterceptorChain(){
        interceptors = new ArrayList<>();
    }
    public static MessageInterceptorChain createNew(){
        return new MessageInterceptorChain();
    }

    public MessageInterceptorChain add(MessageInterceptor interceptor) {
        if (!interceptors.isEmpty()) {
            MessageInterceptor front = interceptors.get(interceptors.size() - 1);
            front.setNext(interceptor);
        }
        interceptors.add(interceptor);
        return this;
    }

    public Promise<Buffer> handle(ServerWebSocket webSocket, Buffer buffer) {
        Promise<Buffer> result = Promise.promise();
        if (interceptors.isEmpty()) {
            result.complete(buffer);
        } else {
            MessageInterceptor interceptor = interceptors.get(0);
            exec(interceptor, webSocket, buffer, result);
        }

        return result;
    }

    private void exec(MessageInterceptor interceptor, ServerWebSocket webSocket, Buffer buffer, Promise<Buffer> result) {
        Promise<Buffer> promise = interceptor.handle(webSocket, buffer);
        promise.future()
                .onSuccess(msg -> {
                    if (!interceptor.hasNext()) {
                        result.complete(msg);
                    } else {
                        exec(interceptor.next(), webSocket, msg, result);
                    }
                })
                .onFailure(result::fail);
    }

}
